By MICHAEL COOPER

Published: November 8, 2006

Eliot Spitzer, who made a name for himself attacking wrongdoing on Wall Street, now faces a more formidable task as governor: overhauling a moribund state government that has been called the most dysfunctional in the nation.

Mr. Spitzer, a Democrat, is about to learn that his campaign promise -- ''Day 1, everything changes'' -- may not be so easy to fulfill when he is faced with a famously intransigent State Legislature and entrenched interests that have long grown used to getting their own ways in Albany. Given the realities of Albany, changing things much in his first 100 days, or first year, or first term could be a tall order.

The Spitzer agenda is an ambitious one: on the stump he has spoken about reviving the stagnant upstate economy, resolving the lawsuit that ordered billions of dollars more in spending on New York City's schools, cutting property taxes, expanding health care coverage while reining in health care costs and reforming an entrenched state government in Albany.

To accomplish much of what he wants to do, Mr. Spitzer will not only have to take on the lobbyists and the powerful special interests who showered money on his campaign, but he will also need to win over a politically divided Legislature that will probably be under the same leaders who were responsible for the infamous gridlock under three terms of Gov. George E. Pataki.

Mr. Spitzer spoke of his lopsided victory as a mandate for change.

''Our agenda is not without ambition, and the road ahead will not be without difficulty,'' he said last night. ''And that is why, to get there, I truly believe it will take more than just a new governor or a new party.''

''The New York we seek will require a new brand of politics, a break from the days when progress was measured by the partisan points you scored or the opponents you beat,'' he said. ''From here on out we need a politics that binds us together, a politics that's forward-looking, a politics that asks not what's in it for me, but always what's in it for us.''

On paper, at least, New York's governorship is one of the most powerful in the nation, and it has attracted similarly outsized personalities, like Theodore and Franklin D. Roosevelt, Al Smith and Nelson A. Rockefeller. But over the last few decades, the Legislature has re-established itself with a fury to rein in the governor's power. Where it was once reluctant to pass bills that a governor had threatened to veto, in recent years it has gleefully overridden vetoes again and again. Enter Mr. Spitzer. As attorney general, he was seen as more iron hand than velvet glove, as many a Wall Streeter can attest. But aides to Mr. Spitzer said that he has three strategies to try to get his agenda through the Legislature.

Mr. Spitzer, they say, hopes to share the credit and make everyone come out a winner when big items are tackled, to try to set an example of doing things on their merits, in a nonpartisan way, to build support for them -- and to fight tooth and nail if the first two strategies fail.

Complicating matters for Mr. Spitzer is the reality that the Legislature has proved extremely adept at insulating itself from accountability to the voters, whether through laws that let incumbent lawmakers draw their own district lines to virtually ensure re-election, or through lax campaign- finance laws that allow large donations, and that make it easy for political parties to funnel huge sums of money to aid the rare endangered incumbent.

Mr. Spitzer has roundly denounced these practices. But if he takes aim at them right away, he risks souring his honeymoon period and endangering parts of his agenda. If he does not, though, he risks finding himself where many a governor has found himself before: frustrated again and again by lawmakers who risk no retribution at the polls.

Michael Waldman, the executive director of the Brennan Center for Justice at New York University School of Law, which branded New York State's Legislature the most dysfunctional in the nation, said Mr. Spitzer has his work cut out.

''This is potentially a reform moment that comes along once every generation or two, where people broadly are fed up, where candidates get elected with specific mandates,'' he said. ''But reform moments don't always turn into reform. Spitzer has a big agenda, and it won't be easy. ''He's been very gutsy in laying out an agenda that was much more specific than it had to be, and he can claim a mandate for it. But the Legislature is still the same Legislature. And governors and presidents with big electoral mandates don't always get the deference from Legislatures that they want.'' No relationships in Albany are more complicated, or more important, than those among the three men who actually run the state: the governor, the Assembly speaker, and the majority leader of the State Senate. Agendas can live or die based on those relationships.

Mr. Spitzer has taken pains not to attack the speaker, Sheldon Silver, who has been the lone Democrat in the ruling triumvirate for the last 12 years and has often taken heat for being an obstructionist as he angled for leverage to achieve his priorities. But their relationship took an awkward turn in recent weeks, after Mr. Spitzer withdrew his endorsement of State Comptroller Alan G. Hevesi, who used a state worker as a chauffeur for his wife, while Mr. Silver continued to publicly support the comptroller.

And it is hard to know what Senator Joseph L. Bruno, the majority leader in the Republican-controlled Senate, will be like in his new role as the odd Republican out. Mr. Bruno has long espoused a get-it-done philosophy, and has shown himself to be ideologically flexible. But he has been unhappy with Mr. Spitzer in recent weeks as Mr. Spitzer has campaigned with gusto against some of the Republican senators Mr. Bruno needs to maintain his slim majority.

Mr. Silver and Mr. Bruno have proved more than willing in recent years to put their partisan interests aside in order to do something they both like: gang up on the governor, usually in the hope of spending more money at budget time. So Mr. Spitzer, like all governors, will have to learn to play their form of three-dimensional chess.

Mr. Hevesi's re-election, too, is already casting a long shadow over Mr. Spitzer's agenda. Mr. Spitzer said that Mr. Hevesi's ability to do his job was compromised. But if Mr. Hevesi does not resign -- and he made clear last night that he intends to serve -- Mr. Spitzer could find himself instigating a messy removal trial in the State Senate that would dominate and probably undermine his honeymoon period, making it hard for him to accomplish his goals.

Gerald Benjamin, a political scientist and the dean of the College of Liberal Arts and Sciences at the State University at New Paltz, said a governor's first year often holds out the most promise for getting things done. ''It's the best year,'' he said. ''Everyone is most distant from re-election, staffers might have aspirations to join the executive branch, legislators may want to be judges or commissioners, there is a wellspring of positive predisposition to the new governor.''

Mr. Spitzer made his broad ambitions clear last night, calling his success ''a victory not of one candidate or one party, but of all those irrepressible optimists who have hoped and dreamed of a resurgent New York.''

Photo: LAST CAMPAIGN STOPS -- Eliot Spitzer and Andrew M. Cuomo campaigned on Election Day at a subway station in Manhattan. (Photo by James Estrin/The New York Times)(pg. P15)